
Partitioning a disk into several volumes
Partitioning a disk divides it into sections, called "volumes." Each volume works like a separate disk. For example, you might partition your computer's hard disk so that you can use one volume as your startup disk with your applications and working files, and the other as a place to back up or archive files.
Partitioning a disk erases all the files on the disk. If you have any files on the disk you want to save, be sure to make a copy of them on another disk before you partition the disk.
You can specify the number of volumes and the size of each one. If you want to use one volume as your Mac OS X startup disk, be sure it's large enough to install the Mac OS X software and any applications and files you will use. Mac OS X requires at least 2 GB of disk space or 3.5 GB if you install the developer tools. Additional disk space is useful if you use many applications at one time.
In addition, you choose a format for the partitions, which is usually Mac OS Extended (Journaled). Each partition can have a different format.
If you want to partition a disk to use with Windows computers, you need to click the Options button and choose Windows Partition Scheme from the pop-up menu. You can then choose an MS-DOS format.
- If you are partitioning an external hard disk, make sure it is connected to your computer.
- In Disk Utility, select the disk that you want to partition in the list.
- Click Partition.
- Choose the number of partitions from the Volume Scheme pop-up menu.
- Click each partition and type a name for it, choose a format, and type a size. You can also drag the divider between the partitions to change their sizes.
If you will use a volume as a Mac OS 9 startup disk, select the checkbox to install the Mac OS 9 drivers. You do not need to install these drivers to use the disk with the Classic environment.
If you will use the drive on a Windows computer, click Options and choose PC Partition Scheme from the pop-up menu.
- Click the Partition button, then click Partition again.
After you partition a disk, a disk icon for each volume appears in the list of disks and volumes. You will also see the volumes in the sidebar of Finder windows.
To partition your computer's startup disk, you must start up using another disk with Mac OS X installed. For example, you can use the Install Mac OS X disc.